Avalanche Forecast

Issued: Mar 17th, 2023 1:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs, Deep Persistent Slabs and Cornices.

Avalanche Canada mkoppang, Avalanche Canada

Email

Pay attention as you climb into Treeline and Alpine areas for the presence of windslabs in the upper snowpack. The sun is packing a punch these days so keep overhead terrain and aspect in your mind as you travel. As it warms up stability will decrease on these aspects.

Summary

Confidence

Moderate

Avalanche Summary

Forecaster were out of the field by 1400 and had observed no new avalanche activity by this time. It would seem the more widespread natural avalanche cycle is beginning to taper.

Snowpack Summary

Recent storm snow has settled into a pleasant 20cm of settled snow. So far the winds haven't made an appearance which means we've been spared a widespread wind slab problem. There are some wind slabs still lurking in the alpine, but they generally seem to be high and in steep alpine terrain. But there is a catch (when isn't there?), the March 12th crust (solar) or facet (polar) layer is a slippery one and it doesn't need much of a cohesive surface layer to pose a problem. Unsupported alpine and treeline terrain is still concerning. The mid to lower pack remains variable, in every sense of the word. The depth changes dramatically on elevation, and the supportiveness of it seems to change at the drop of a hat. Thin spots and rocky areas are still a likely place to trigger the deeper problem layers.

Weather Summary

The high pressure ridge overhead is forecast to continue into Saturday. Temperatures will start at -18 and rise to -3 by early afternoon with a freezing level forecast to be around 2000m. The solar input was noticeable today, expect the same strong inputs on Saturday. As for the wind, only light breezes are expected for the next few days. Beautiful touring at the moment out there!

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Cornices become weak with daytime heating or solar exposure.

Problems

Wind Slabs

An icon showing Wind Slabs

Watch for windslabs in immediate lees along ridgelines and in gullied terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The alpine is still variable in total amounts of snow but the basal layers haven't changed. The entire lower half is either facets, or depth hoar. Thin weak areas should be treated as suspect and avoided.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3.5

Cornices

An icon showing Cornices

Avoid travelling near or below cornices as these will become weak with daytime heating.

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 18th, 2023 4:00PM